Emotional responses to music were once viewed as so subjective and difficult to measure that few researchers dared to attempt studying them in the laboratory. Luckily today, mapping the neural correlates of musical emotions has become a central quest in music-related neuroscience. Brain imaging studies in recent decades have revealed that music has the power to influence some of the same neural systems that underlie emotions in general. These neural systems do not seem to care whether your emotions are elicited by music or by something more concrete, such as receiving a gift or being reminded of a sad-life event.

A recent study in this line of research used functional magnetic resonance imaging (fMRI) to identify the brain regions that are active during affective responses to three different pieces of classical music (Trost et al., 2015). Unlike many previous studies, this study also attempted to identify moments in the musical pieces when the subjects showed similar brain activity, in other words, moments when the participants’ brains became synchronized. The subjects rated the moment-by-moment fluctuations in the valence (i.e. pleasantness vs. unpleasantness) and arousal they felt while listening to the musical pieces. The researchers then looked for regions in the brain whose synchronous activations increased and decreased with these changes in arousal and valence.

The louder and more dissonant the music, the less activity there was in subcortical structures that are important for emotions

The researchers found that synchronous activations in the deep-brain structures important for emotions such as the amygdala, insula and caudate nucleus increased with higher arousal. Positive valence in turn was linked to decreased activity in the amygdala and caudate. Synchrony across subjects was also found in a region implicated in reward processing, the nucleus accumbens. Interestingly, the study also found that the activity in some these regions could be predicted by acoustic features of the music. For example, the louder and more dissonant the music, the less activity there was in subcortical structures that are important for emotions.

The identified areas are part of the neural networks that are known to be important for emotions not only in music but also outside the musical domain. Thus, this study is in line with previous findings showing that music can recruit core neural mechanisms of emotions. The study also shows that brain activity during music listening can at times be fairly similar across individuals. But as the authors note, it is probably also true that emotional responses are idiosyncratic to some degree and looking only at the moments when subjects show highly similar brain activity misses such individual differences. Surely, much remains to be investigated regarding how musical emotions are enabled by the brain.